There are two different high-speed duplication methods in common usage in video recording facilities. The first method employs the use of Curie-temperature thermoremanence effects to produce duplicated recordings on bulk pancakes of copy tape from a mirror-image master tape. The second method employs anhysteretic effects to produce copies from a higher-coercivity mirror-master tape. Each system has a number of advantages and drawbacks.
For the thermomagnetic process, the disadvantages are centered around the requirement that CrO.sub.2 copy tape be used, which commands a significant price premium in the marketplace, and is available only from a dwindling number of suppliers. The thermomagnetic process also requires the use of a high-powered ND-YAG laser to provide the necessary heating to the copy tape oxide layer. This laser system has significant maintenance costs and consumes large quantities of electricity, thereby generating substantial heat which must be removed by water cooling facilities. In addition, available thermomagnetic duplication equipment utilizes a vertical loop-bin configuration to house the mirror-master tape, and the speed of operation of this unit is limited by static electricity effects, even as the master-program-length is limited by the physical capacity of the loop-bin. The major advantages of the system are the generally excellent tape-handling characteristics, and the high quality of the copies produced.
As for the anhysteretic process, the disadvantages of the currently available duplication equipment are related to the lack of loop-bin facilities in those models utilizing a vertical configuration of the equipment, and in the large amount of floor space required for the loop-bin incorporated in-horizontal configurations. In addition, the use of stationary (non-rotating) tape guides in both of these configurations results in problems due to tape oxide shedding. Furthermore, the price of the horizontal configuration equipment is cost-prohibitive for many duplication companies. Advantages for this type of system include relatively low maintenance and operating costs, and the ability to utilize any type of magnetic tape.